The Vans Warped Tour made its annual stop yesterday at the First Niagara Pavilion, where, in the spirit of American commerce, everyone was selling something.

Vans was selling T-shirts and skateboard shoes.

The Pavilion was selling $4.50 bottles of water to people melting in the 90-degree heat.

Metalcore bands were selling angst with a side of rage.

Pop-punk bands -- energy and sex appeal.

The emo acts ... feelings, of course.

And then there was Andrew W.K., selling nothing but a PARTY.

One of the marquee stars of the tour, the rock 'n' roll madman hit the stage at 6:20 with the most galvanizing set of the day, one sure to exorcise the place of any bad vibes that may have hovered earlier.

It was smiles all around as Andrew, in his trademark whites and swinging hair, headbanged through punk-rock celebrations such as "It's Time to Party" and "You Will Remember Tonight" like a modern-day Jerry Lee Lewis.

He gave people the shirt off his back, not once but twice, while urging them to have fun and repeatedly expressing his love for them. For the rousing finale of "Party Hard," fans stormed the stage to hoist him up like he'd just rolled two kegs into the frat party.

The rest of the day offered a stylistic span just as capable of causing whiplash.

On one, extreme end were deathcore worshippers Whitechapel, who sounded like the pit band in hell, and Suicide Silence, who managed to make every song like ... the crazy end of a song.

One flipside was a band like Hey Monday, with pop hooks as sweet as the free Wonka gummies. The band was part of a newish wave of Warped pop that included solo artist Mike Posner doing his "Cooler Than Me" hit and remixing Beyonce, among others; Kelsey and the Chaos actually covering Ke$ha; and Never Shout Never inspiring something resembling Bieber Fever with his romantic acoustic pop.

The biggest crowd of the day gathered around All-American Rejects, who upped the energy to another level on hits like "Dirty Little Secret" and "Move Along." White-suited hearthrob Tyson Ritter acknowledged that dudes won't admit to digging them and asked that we not "be afraid to like good rock 'n' roll." Didn't seem like a problem yesterday.

Fans of peppy pop-punk got a big kick out of Sum 41, still a pretty tight, talented unit that ricocheted through a playful set loaded with familiar sing-alongs like "Fat Lip" and "Still Waiting." It was funny -- and sad -- to see those fans run for the hills as soon as Rev. Peyton's Big Damn Band followed with big-bellied, rip-roaring hillbilly punk on steel guitar and washboard.

Old school punks are a dying breed at Warped, but they were in good hands with The Bouncing Souls, capable of thrashing or doing it reggae style; Face to Face, playing that kind of serious punk a la Bad Religion that doesn't have the pop in front of it; and mohawk-powered street punks The Casualties, who roared like it was 1980 on shout-along anthems such as "Tomorrow Belongs to Us" and a cover of 'Blitzkrieg Bop."

The band most deserving of a bigger stage was the Riverboat Gamblers, Texas garage-punks who played one of the day's most riveting sets basically on the back of a truck, severely limiting manic frontman Mike Wiebe's climbing and falling potential.

After enduring eight and a half hours of oppressive heat, hunger, dehydration and pummeling noise, there was one last challenge to the fans, delivered by screamo band Bring Me the Horizon: a wide circle pit around the sound tent. As a testament to youth, sure enough the day ended with the climax to "Braveheart."

Critics Andrew Druckenbrod and Scott Mervis talk about music on "The Beat," available exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.